Astigmatism

What is astigmatism?

Astigmatism occurs when cornea is curved more in one direction than in the other. The shape of the eye is more similar to a football than a rugby ball. The prevalence of astigmatism is highest in infancy and childhood. Rays focus at several points (in front and/or behind the retina). Near and distant vision is affected.

What causes astigmatism?

The child usually born with astigmatism though many are insignificant visually. The amount of astigmatism usually does not change with age.

What are the symptoms of astigmatism?

Blurring vision and squinting eyes to see are often the common symptoms and astigmatism more than one diopter is a significant risk for amblyopia.

How is astigmatism treated?

Cylindrical power glasses are prescribed for significant astigmatism, which, if not corrected, can lead to amblyopia. Contact lenses and laser surgery are alternatives to glasses when the child is older, usually 20 years or more when the focusing power in the eye stabilized.

Educational Implications

Behaviours or conditions that might indicate astigmatism

• Blurry or fuzzy vision when viewing near or distant information.
• Eye strain.
• Visual fatigue.
• Not interested in reading or near visual tasks.
• Squint to help focus when looking at near information.

What to do

• The young person should visit an optometrist to determine diagnosis and to be fitted for glasses with corrective lenses or contact lenses.
• When using glasses with corrective lenses or contact lenses, persevere. Try to engage the young person with something interesting and diverting to become more accustomed with the corrective view through the lenses when looking at near information.
• If the child’s vision fail to improve with correcting glasses then the child should be reviewed by ophthalmologist to make sure the diagnosis is correct.
• If the young person finds it challenging to wear glasses or contact lenses, review whether the issue is one of comfort or whether the lenses may no longer be accurate. When a young person chooses not to wear prescription glasses and/or contact lenses and comfort has been ruled out, it might indicate that the prescription is no longer helpful and may need to be reviewed or that the young person is not experiencing any consistent, obvious and functional benefit from the correct prescription lenses and a review may be required.
• It is important that the young person take visual breaks and allow their eyes to relax.